Is a black belt someone that can defeat everyone else in the world with a lower belt? That’s absurd on its face. An older, smaller, or recreational black belt might struggle to tap a young, big, competitive lower belt.
So how do you measure what a belt means?
Although we strive for as much objectivity as possible and superimpose the reality of live sparring, fundamentally we can only measure ourself in relation to ourself. All other measurements are imperfect.
Rener and Ryron Gracie say that every 20 pounds or 10 years is equal to a belt level. What they mean is that if both you and your opponent are blue belts, if he’s 20 pounds heavier or 10 years younger, the impact would similar to you going against a purple of exactly your size and age (unless of course you’re 10 years old, in which case you’d be fighting an embryo. And that’s just weird.).
I tend to view 20 pounds or 10 years as a rounding error, but the principle behind it is sound: Physical attributes matter. And they matter a lot. Once you accept that, it makes training a lot easier because you are less prone to setting unrealistic expectations for yourself.
Look, we want to believe that Jiu Jitsu is magic. It’s not. That’s why there are weight classes and gender categories in competition. If there weren’t, with few exceptions all the world champions would be the biggest, most athletic men. The only way to be a 160 pound world champion is when you are facing other 160 pounders.
So the idea that a purple belt is someone that can beat all blue belts is nonsense. There are too many other variables. Of course an average purple belt should have objectively measurable better technique than an average blue, but that alone doesn’t determine effectiveness. It’s the combination of technique and attributes.
It’s a universal desire to represent ones belt perfectly. I’ve been susceptible to that plenty of times. Even when you understand that size, strength, and athleticism matter you’re not immune to feeling bad that you can’t overcome it. No one likes having difficulty tapping a lower belt (or being tapped by one). It can be very humbling. But the first and most important step is to acknowledge that our effectiveness is based on the sum total of who we are both physically and mentally. And we are not all equal in that regard.
Competition is probably as close as you can get to measuring your skill relative others because you’re going against athletes at your belt and weight. But even then it’s imperfect. A new blue belt going against a blue on the cusp of purple is unlikely to fare very well. Plus, the competition scene these days is full of physically gifted people at every level who train like pro athletes. That’s a very high bar. There’s also a ton of specialization and strategy. Competition is a game, and like all games, the person who is best at not only playing the game but gaming the game usually wins.
So at the end of the day your only reliable measuring stick is you. Are you a blue belt compared to the person you were when you walked in the door on your first day of class? If the answer is yes, then you’re a blue belt.